John o bkien



J. OBBIEN.

Grate Damper.

Patented Dec. 15', 1857.

N PEYEBs, FhomLnhc m he-r. Washnnglom D c.

UNITED STATES PATENT OFFICE.

JOHN OBRIEN, OF NEW YORK, N. Y., ASSIGNOR TO OWEN COLLINS AND JOHNDUNLEY, OF SAME PLACE.

GRATE-DAMPER.

Specification of Letters Patent No. 18,885, dated December 15, 1857.

To all whom it may concern:

Be it known that I, JOHN OBRIEN, of the city, county, and State of NewYork, have invented a new and useful Improvement in Dampers for OpenGrates; and I do hereby declare that the following is a full, clear, andexact description of the same, reference being had to the accompanyingdrawings, making a part of this specification, in which Figure 1 is atransverse vertical section of a grate, with my improvement applied toit, which improvement is also bisected, (an) (m) in Fig. 2 showing theplane of section. Fig. 2 is a front view of the same.

Similar letters of reference indicate corresponding parts in each of theseveral figures.

The invention is designed to obviate the objection to open grates, viz.,the great consumption of fuel occasioned by the large amount of heatwhich passes up the chimney or flue.

To enable those skilled in the art to fully understand and construct myinvention, I will proceed to describe it.

A, represents an open grate of the usual construction, and B is myimproved damper placed some distance above the grate. This damper isformed of a rectangular cast iron frame (a) which is fitted between jaws(b) one at each end of the flue. The frame (a) is cast with horizontalbars (0) across it. These bars are of V-form, transversely, as shownclearly in Fig. 1, and any proper number may be used. Three, however,are shown in the drawings.

Within the frame (a) a frame (d) is fitted, the lower end of the frame(at) being connected by joints (6) to the lower end of the frame, (a).The frame (d) is cast with horizontal bars (f), which, when the frame(d) is upon the frame (a), will fill the spaces between the bars (0).This is clearly shown in Fig. 1. The bars (f) are each provided with aflanch which flanches project out at right angles from the bars (f).

The frame (a) is placed in an inclined position, as shown clearly inFig. 1, and when a full or strong draft is desired the frame is thrownback, as shown in red in Fig. 1, the passage of the full or strong draftbeing indicated by the red arrows in Fig. 1. A medium draft is obtainedby having the frame (d) secured a short distance back from the frame(a). When a small or weak draft is only desired, the frame (at) isallowed to rest upon the frame (a). By this means the damper willbenearly but not entirely closed, for the bars do not come in contact withthe bars (0), and the openings or spaces between the edges of the bars(f) and the back edges of the bars (0) are sufficiently wide to allowthe gas to escape up the chimney or flue, but not the heat, the draftbeing merely suflicient to keep up the necessary combustion and carryoff the gas. The black arrows show the direction of the gas.

The V-form of the bars (0) and the flanches (g) on the bars (f) are forthe purpose of deflecting the heat, and causing it to be thrown out intothe room, as indicated by the arrows 1.

I am aware that dampers for open grates have been previously devised forthe same purpose. A perforated damper was recently patented; but it doesnot fully answer the intended purpose. The perforated openings cannot beenlarged nor contracted, and chimneys vary so very materially as regardstheir strength of draft that the perforated damper will suit in somecases and not in others. When fitted in some chimneys, the draft is notsufficiently strong to carry off the gas, and when fitted in others thedraft is strong enough to allow a vast amount of heat to pass through.the perforated damper and up the chimney.

I do not claim, broadly, the employment of dampers composed of twoparts, one of which is provided with angular projections, for I am awarethat an example of such a device is seen in the rejected application ofJ. H. Wilkinson, May 28, 1856. But in the above device one portion ofthe damper slides over the other, rendering its application tofire-places or its use as a gratedamper, diflicult if not impossible.But by hinging the frames (a) and (d) together, as herein shown, thedamper becomes perfectly adapted to the fire-place, and forms a new andhighly useful improvement.

I would remark that the frame (01) may be retained at any point by a rod(h) having a projection upon it, said rod passing through a slot in oneside of the frame.

It will be seen that my improved damper may be adjusted to suit thedraft, and therefore the invention may be advantageously I (d), When oneof said frames (d) is hinged applied in all cases. to the other frame(a), as and for the pur- Having thus described my invention, posesherein specified.

What I claim as new, and desire to secure by JOHN OBR-IEN. 5 LettersPatent, is: Witnesses:

The employment Within a fire-place, of a OWEN COLLINS, damper B,composed of two frames (a) and JOHN DUNLAY.

